Purification and identification of a polysaccharide from medicinal mushroom Amauroderma rude with immunomodulatory activity and inhibitory effect on tumor growth

Medicinal mushrooms in recent years have been the subject of many experiments searching for anticancer properties. We previously screened thirteen mushrooms for their potential in inhibiting tumor growth, and found that the water extract of Amauroderma rude exerted the highest activity. Previous studies have shown that the polysaccharides contained in the water extract were responsible for the anticancer properties. This study was designed to explore the potential effects of the polysaccharides on immune regulation and tumor growth. Using the crude Amauroderma rude extract, in vitro experiments showed that the capacities of spleen lymphocytes, macrophages, and natural killer cells were all increased. In vivo experiments showed that the extract increased macrophage metabolism, lymphocyte proliferation, and antibody production. In addition, the partially purified product stimulated the secretion of cytokines in vitro, and in vivo. Overall, the extract decreased tumor growth rates. Lastly, the active compound was purified and identified as polysaccharide F212. Most importantly, the purified polysaccharide had the highest activity in increasing lymphocyte proliferation. In summary, this molecule may serve as a lead compound for drug development.     

High-resolution phylogeny providing insights towards the epidemiology,zoonotic aspects and taxonomy of sapoviruses

The evolution, epidemiology and zoonotic aspects of Sapoviruses (SaV) are still not well explored. In this study, we applied high-resolution phylogeny to investigate the epidemiological and zoonotic origins as well as taxonomic classification of animal and human SaV. Bayesian framework analyses showed an increase in porcine SaV (PoSaV) population dynamics and genetic diversity between 1975 and 1982, resulting in a SaV gene flow and generation of new strains among porcine and human populations. Our results also show the contribution of different animal populations involved in SaV epidemiology and highlight zoonotic aspects, as exemplified by the crucial role that swine, dogs, mink and humans play in SaV spread. Additionally, phylogenetic analysis suggests that bats may play key role in SaV epidemiology. According to our hypothesis, these animals may act as reservoirs or intermediate host species, contributing to viral spread in zoonotic and other epidemiological scenarios and facilitating the generation of new SaV genogroups and genotypes through recombination events. Data from large-scale phylogeny partition based on patristic distance, did not show a correlation between transmission clusters on generation of SaV genogroups, nevertheless we present both important findings about SaV taxonomy and important considerations useful for further taxonomical studies.     

Genome characterization of a GII.6 norovirus strain identified in China

Noroviruses (NoVs) are the primary cause of non-bacterial acute gastroenteritis worldwide. Most NoV infections are caused by GII.4, but GII.6 is also an important genotype with a long-term persistence in human populations. In this study, the complete genome sequence of a NoV strain GZ2010-L96 isolated in China was identified and analyzed phylogenetically. The viral genome comprised 7550 nucleotides, and its phylogenetic analysis revealed that the strain belonged to GII.6 genotype. All reported GII.6 NoV capsid protein sequences were also collected for comparative analysis, and GZ2010-L96 was clustered into GII.6-b with other 8 strains. Meanwhile, it was found that 53 spots on viral capsid showed subcluster specificity according to multiple alignments. Moreover, homologous modeling of GZ2010-L96 based on comparison with GII.4 VA387 strain showed a different antigen distribution pattern. In summary, the genome of the GII.6 strain GZ2010-L96 detected in China was extensively characterized, and phylogenetic analyses of GII.6 NoVs based on the capsid proteins may reveal a different evolution process from the predominant genotype GII.4.     

Two new 12-membered macrolides from the endophytic fungal strain Cladosprium colocasiae A801 of Callistemon viminalis

Two new polyketide metabolites, the 12-membered macrolides 4-hydroxy-12-methyloxacyclododecane-2,5,6-trione (1) and 12-methyloxacyclododecane-2,5,6-trione (2), were isolated from the endophytic fungal strain Cladosprium colocasiae A801 of the plant Callistemon viminalis, together with five known derivatives. Their structures were fully characterized by means of detailed spectroscopic analysis for new structures, and in comparison with published data for known compounds. The antibacterial, cytotoxic, and α-glucosidase inhibitory activities of the new compounds 1 and 2 were evaluated.     

Evaluation of wondfo rapid diagnostic kit (Pf-HRP2/PAN-pLDH) for diagnosis of malaria by using nano-gold immunochromatographic assay

Prompt and accurate diagnosis is necessary to start adequate treatment for different affecting species including P. falciparum and P. vivax. Here we described the Wondfo Rapid diagnostic Kit (Pf-HRP2/PAN-pLDH) for the detection of P. falciparum and pan-plasmodium in patient specimen by using a nano-gold immunochromatographic assay. Our rapid assay adapted nano-gold labeling techniques and the monoclonal antibodies (mAbs) against both histidine rich protein-2 (Pf HRP-2) of P. falciparum and pan plasmodium-specific pLDH (pan pLDH). The established two-antibody sandwich immunochromatographic assay could detect P. falciparum and pan-plasmodium. The sensitivity and specificity of Wondfo rapid diagnostic kit were determined by comparing with the “gold standard” of microscopic examination of blood smears. In this study1023 blood samples were collected from outpatient clinics in China and Burma, and detected by both Wondfo kit and microscopic examination. The detection sensitivity and specificity of Wondfo rapid diagnostic kit were 96.46% and 99.67% for P. falciparum (HRP2), 95.03% and 99.24% for pLDH, 96.83% and 99.74% for non-falciparum species, 96.70% and 99.74% for P. vivax, respectively. These results indicate that Wondfo rapid diagnostic assay may be useful for detecting P. falciparum and non-P. falciparum (especially P.v.) in patient specimen.     

南海海洋真菌帚状弯孢聚壳次级代谢产物及其抗肿瘤活性研究

目的研究南海海洋真菌帚状弯孢聚壳Eutypella scoparia的次级代谢产物及其抗肿瘤活性。方法采用硅胶柱、反相硅胶柱、凝胶柱和薄层制备等色谱技术和重结晶进行分离纯化,通过波谱分析进行结构鉴定;以神经胶质瘤细胞SF-268、乳腺癌细胞MCF-7、大细胞肺癌细胞NCI-H460为供试细胞株,采用MTT法对化合物进行体外抗肿瘤活性研究。结果从发酵物中分离并鉴定了10个化合物,其中6个为海松烷型二萜,分别为isopimara-8(14),15-diene(1)、libertellenone A(2)、scopararane B(3)、diaporthein A(4)、diaporthein B(5)、11-deoxydiaporthein A(6);4个为麦角甾醇类化合物,分别为麦角甾酮(7)、麦角甾醇(8)、过氧化麦角甾醇(9)、啤酒甾醇(10),其中化合物5对3种肿瘤细胞株的IC50分别为9.2、4.4、9.9μmol/L。结论化合物1、2和6～10均为首次从该属真菌中分离得到,化合物5具有显著的细胞毒活性。     

沉香DNA的提取及其ITS2-PCR体系的优化

目的:建立沉香的总DNA提取方法及r DNA第二内转录间隔区序列(ITS2)聚合酶链式反应(PCR)扩增体系。方法:分别采用改良的CTAB法、改良的CTAB法联合DNA提取试剂盒法及DNA提取试剂盒法提取沉香总DNA,利用通用引物ITS2P1/ITS2P2扩增r DNA ITS2目的片段,通过正交试验优选沉香的PCR扩增条件并对目的片段进行测序。结果:改良的CTAB法联合DNA提取试剂盒法提取总DNA的A260 nm/A280 nm1.79,质量浓度350 mg·L-1,PCR扩增目的片段产率最高。不同因素水平对沉香ITS2-PCR反应的影响顺序为模板DNA引物Taq DNA聚合酶d NTP。最佳反应体系为20μL体系,DNA模板40 ng,引物0.2 mmol·L-1,d NTP 0.5 mmol·L-1,Taq DNA聚合酶1.5 U。测序获得的目前片段长度230 bp,与Gen Bank中瑞香科沉香属白木香序列相似性100%。结论:CTAB法联合DNA试剂盒法可简单、快速获得高质量沉香总DNA,正交试验可快速获得ITS2目的片段,为沉香的分子鉴定和系统发育分析提供参考。     

白木香倍半萜合成酶As-SesTPS1基因的克隆、生物信息学和表达分析

目的基于前期对白木香Aquilaria sinensis转录组测序结果,从白木香总RNA中克隆白木香倍半萜合成酶基因(As-Ses TPS1),并对其进行生物信息学及表达分析。方法利用逆转录聚合酶链式反应(RT-PCR)从白木香总RNA中获得倍半萜合成酶基因As-Ses TPS1的c DNA全长序列;利用生物信息学手段对该序列进行相似性和同源性分析,并预测其编码蛋白的结构和功能;利用q RT-PCR技术检测该基因在白木香不同样品中的表达水平。结果得到倍半萜合成酶基因As-Ses TPS1,开放阅读框(ORF)全长1 671 bp,编码556个氨基酸,其与多条倍半萜合成酶基因具有较高相似性,并含有RRx8W和DDxx D的保守序列;该基因在白木香的沉香样品中高表达。结论 As-Ses TPS1的克隆及其生物信息学和在白木香不同部位表达差异性分析,为白木香倍半萜生物合成代谢途径的研究奠定基础。     

三角褐指藻在多波长下藻液吸光度与细胞密度的关系研究

目的研究具潜在药用价值的三角褐指藻Phaeodactylum tricornutum在不同波长下,其藻液吸光度与细胞密度的关系。方法取对数生长后期的三角褐指藻藻液进行梯度稀释,利用显微镜观测微藻细胞密度,利用分光光度计分别测定藻液在8个波长下的吸光度,分析各波长下微藻细胞密度与吸光度的相关性。结果 6个稀释梯度下的细胞密度分别为923×104、453×104、207×104、94×104、47×104、22×104个/mL;不同波长下藻液吸光度有差别。8个波长下,细胞密度与吸光度均存在显著性相关关系,在680、663、420和450 nm波长处相关系数r值较大,分别为0.999 0、0.998 1、0.997 2和0.996 3。结论利用吸光度法检测三角褐指藻细胞生长是一种快速、简便、可行的方法;本试验条件下,在680、663、420和450 nm波长处测定三角褐指藻藻液的吸光度较为适宜。